Skip to content

Latest commit

 

History

History
99 lines (77 loc) · 7.64 KB

threat-modeling.md

File metadata and controls

99 lines (77 loc) · 7.64 KB

Threat Model Analysis for ibireme/yykit

Threat: Image-Based Denial of Service (DoS)

  • Threat: Image-Based Denial of Service (DoS)

    • Description: An attacker crafts a malicious image (e.g., excessively large dimensions, deeply nested GIF layers, or exploits vulnerabilities in underlying image decoding libraries) and uploads it or provides it as input to the application. YYKit attempts to decode or render the image, consuming excessive memory or CPU, leading to a crash or unresponsiveness.
    • Impact: Application crash, denial of service, resource exhaustion, potential device instability.
    • Affected YYKit Component: YYImage, YYAnimatedImageView, potentially underlying image decoding functions used by these components (e.g., within YYImageDecoder).
    • Risk Severity: High
    • Mitigation Strategies:
      • Implement strict size and dimension limits on images processed.
      • Validate image headers and metadata before decoding.
      • Use a sandboxed process for image decoding.
      • Monitor memory/CPU usage during processing; implement timeouts.
      • Regularly update YYKit and its dependencies (ImageIO).
      • Consider a dedicated image processing service.

Threat: Text Rendering Denial of Service (DoS)

  • Threat: Text Rendering Denial of Service (DoS)

    • Description: An attacker provides extremely long or complex text strings (e.g., deeply nested attributed strings, custom layouts) as input. YYText's rendering engine struggles to process this input, leading to excessive resource consumption, crashes, or significant performance degradation.
    • Impact: Application crash, denial of service, resource exhaustion, poor user experience.
    • Affected YYKit Component: YYText, specifically components like YYLabel, YYTextView, and the underlying text layout and rendering engine.
    • Risk Severity: High
    • Mitigation Strategies:
      • Impose reasonable length limits on text input.
      • Validate and sanitize text input before rendering.
      • Monitor rendering performance; implement timeouts.
      • Consider offloading complex text rendering to a background thread.

Threat: Indirect Cross-Site Scripting (XSS) via YYText Misuse

  • Threat: Indirect Cross-Site Scripting (XSS) via YYText Misuse

    • Description: An attacker provides malicious HTML or JavaScript as input. The application incorrectly uses YYText to render this input and then passes the result to a different component (like a UIWebView or WKWebView) that can execute the script. This is a misuse of YYText, leading to an XSS vulnerability.
    • Impact: Execution of arbitrary JavaScript in the context of the web view, potential for data theft, session hijacking, phishing, and other XSS-related attacks.
    • Affected YYKit Component: YYText (misused), but the actual vulnerability is in the web view component (UIWebView/WKWebView).
    • Risk Severity: Critical (if a web view is involved and mishandles the output)
    • Mitigation Strategies:
      • Never use YYText to render untrusted HTML/JavaScript intended for a web view.
      • Use a properly configured WKWebView with security measures (CSP, sandboxing).
      • Sanitize all user input before any rendering, regardless of the component.

Threat: Cache Poisoning

  • Threat: Cache Poisoning

    • Description: An attacker manipulates user input that is used (directly or indirectly) to generate cache keys. By crafting specific input, the attacker can cause the application to store malicious data in the cache, which is then served to other users.
    • Impact: Serving incorrect or malicious data to users, potential for data corruption, application misbehavior, and potentially even code execution (depending on how the cached data is used).
    • Affected YYKit Component: YYCache, specifically the key-value storage mechanisms (setObject:forKey:, objectForKey:, etc.).
    • Risk Severity: High
    • Mitigation Strategies:
      • Use strong, unpredictable cache keys; avoid direct use of user input.
      • Hash or transform user input before incorporating it into keys.
      • Implement cache validation to ensure data integrity.
      • Use separate cache instances for different trust levels.

Threat: Cache Information Disclosure

  • Threat: Cache Information Disclosure

    • Description: Sensitive data is stored in the YYCache without proper encryption or access controls. An attacker with access to the device's file system (e.g., jailbroken device) can read the cache contents.
    • Impact: Leakage of sensitive data (user credentials, API keys, personal information), potential for identity theft or other malicious activities.
    • Risk Severity: High
    • Mitigation Strategies:
      • Encrypt sensitive data stored in the cache (YYCache supports encryption).
      • Use appropriate file system permissions.
      • Consider the Keychain for highly sensitive data.
      • Implement a cache eviction policy.

Threat: Insecure Deserialization in YYModel

  • Threat: Insecure Deserialization in YYModel

    • Description: The application uses YYModel to deserialize data from an untrusted source (e.g., user input, external API) without proper validation. An attacker injects a malicious payload that, when deserialized, leads to arbitrary code execution or other vulnerabilities.
    • Impact: Remote code execution (RCE), complete application compromise, data theft, potential for device compromise.
    • Affected YYKit Component: YYModel, specifically the model mapping and deserialization functions (e.g., modelWithJSON:, modelWithDictionary:).
    • Risk Severity: Critical
    • Mitigation Strategies:
      • Strictly validate data before deserialization. Use a schema or whitelist.
      • Avoid deserializing data from completely untrusted sources.
      • Consider safer serialization formats (JSON with schema validation).
      • Use a language/framework with built-in deserialization protection.

Threat: Weak Random Number Generation in Utility Functions

  • Threat: Weak Random Number Generation in Utility Functions

    • Description: A utility function within YYKit uses a weak random number generator (e.g., rand()) for a security-sensitive operation (e.g., generating a session ID). An attacker can predict the generated values, compromising the security mechanism.
    • Impact: Compromised security mechanisms (e.g., predictable session IDs, weak encryption keys), potential for session hijacking, data breaches, and other attacks.
    • Affected YYKit Component: Any utility function within YYKit that uses random number generation (check the source code). This is less likely in a well-maintained library, but still worth checking.
    • Risk Severity: High (if used for security-sensitive operations)
    • Mitigation Strategies:
      • Review YYKit utility function source code.
      • Use cryptographically secure random number generators (SecRandomCopyBytes).
      • Avoid relying on YYKit for core cryptographic functions; use dedicated libraries.